By David Morgan
WASHINGTON (Reuters) - A Food and Drug Administration review of CardioMEMS' device for treating heart failure found it has met its main safety and effectiveness goals, based on trial results.
But the FDA questioned on Monday how clinically significant the findings are for the CardioMEMS Champion HF Monitoring System, which undergoes an FDA panel review on Thursday.
The agency's staff said they wanted the outside panel to address questions related to the proportion of patients who were hospitalized for heart failure after receiving the device, the number of days alive outside the hospital and their quality of life.
FDA staff also noted an issue involving nurses working for CardioMEMS who made medication changes for some patients that were beyond the scope of the study's protocol.
"FDA is concerned is that this study tested a treatment strategy of device plus heart failure recommendations (versus) optimal medical therapy alone, which was not FDA's understanding of the original intent of this trial," the document said.
Medical device maker St Jude Medical Inc has a 19 percent stake in CardioMEMS, an Atlanta-based startup. Shares in St Jude rose 4.4 percent, as some analysts said the initial FDA review suggested a favorable recommendation.
A positive recommendation from the FDA panel is expected to lead St Jude -- a St. Paul, Minnesota-based maker of heart pacemakers, implantable defibrillators and heart valves -- to exercise an exclusive option to buy the remainder of CardioMEMS for $375 million.
But Michael Matson of Mizuho Securities USA said the FDA staff questions and the issue involving medication changes reduced the probability of a favorable panel vote to 60 percent from 75 percent.
Formal FDA approval would give CardioMEMS the first implantable stand-alone heart failure diagnostic system in the United States, with a potential domestic market value of $1 billion and the prospect for up to $2 billion more in additional sales worldwide, according to analysts.
The system includes a 15-millimeter-long sensor that can be implanted in the heart's distal artery via catheter. Once there, it monitors pressure within the heart without the need for a battery and transmits its findings to computers that allow the data to be reviewed by physicians and patients.
(Reporting By David Morgan, editing by Gerald E. McCormick, Dave Zimmerman)